Method and apparatus for generator control

Patent metadata

Field	Value
Publication number	US-9979336-B2
Application number	US-201514810738-A
Country	US
Kind code	B2
Filing date	Jul 28, 2015
Priority date	Jul 28, 2015
Publication date	May 22, 2018
Grant date	May 22, 2018

Abstract

A generator system includes an AC machine including a plurality of armature coils and a rectifier circuit electrically coupled to the armature coils. The rectifier circuit includes a plurality of switches. The generator system additionally includes a sensor device electrically coupled to a control circuit. The sensor device is configured to determine a rotor position of the AC machine. The control circuit determines a desired phase angle between a phase current and an induced voltage of the AC machine and provides a control signal to the rectifier circuit to switch the switches on and off to convert an AC signal to a DC signal and to control the rotor position of the AC machine to achieve the desired phase angle.

First claim

The invention claimed is:

1. A generator system comprising:
an AC machine including a plurality of armature coils producing multi-phase AC output voltages;
a rectifier circuit electrically coupled to the armature coils, said rectifier circuit including a plurality of switches; and
a sensor device electrically coupled to a control circuit, said sensor device configured to determine a rotor position of the AC machine;
said control circuit determining rotor speed, determining a desired phase angle between a phase current and respective AC output voltage of the AC machine based upon the rotor speed and the multi-phase AC output voltages, and providing a control signal to the rectifier circuit to switch the switches on and off to convert said multi-phase AC output to a DC output and to achieve the desired phase angle.

2. The generator system of claim 1 wherein the sensor device configured to determine the rotor position of the AC machine comprises a Hall-effect sensor with a predetermined resolution.

3. The generator system of claim 1 wherein determining the desired phase angle between the phase current and the respective AC output voltage of the AC machine comprises using a look-up table.

4. The generator system of claim 1 wherein determining the desired phase angle between the phase current and the respective AC output voltage of the AC machine is further based on achieving an increased output DC current and an increased power of the generator system over a preferred operating speed range.

5. The generator system of claim 1 wherein determining the desired phase angle between the phase current and the respective AC output voltage of the AC machine is further based on achieving an increased efficiency of the generator system.

6. The generator system of claim 1 wherein determining the desired phase angle between the phase current and the respective AC output voltage of the AC machine is based on achieving a faster torque response.

7. The generator system of claim 1 wherein determining the desired phase angle between the phase current and the respective AC output voltage of the AC machine is based on achieving a faster voltage response.

8. A method for controlling a generator comprising an active bridge rectifier circuit including a plurality of switches, said method comprising:
monitoring a sensor device configured to determine a rotor position of an AC machine of the generator, said AC machine producing a multi-phase AC output comprising a plurality of phase voltages;
determining a desired phase angle between a phase current and an induced voltage of the AC machine of the generator based upon the rotor position;
determining phase-to-phase voltages from the plurality of phase voltages;
determining rotor speed;
comparing said phase-to-phase voltages to upper and lower voltage thresholds;
at rotor speeds below a predetermined speed generating a control signal to the active bridge rectifier circuit to switch all switches of the active bridge rectifier circuit off; and
at rotor speeds above said predetermined speed generating a control signal to the active bridge rectifier circuit to control the switches based upon the desired phase angle and the comparison of said phase-to-phase voltages to said upper and lower voltage thresholds to convert said multi-phase AC output to a DC output and to achieve the desired phase angle.

9. The method of claim 8 , wherein determining the desired phase angle between the phase current and the induced voltage of the AC machine of the generator comprises determining said desired phase angle to achieve an increased output DC current and an increased power of the generator system over a preferred operating speed range.

10. The method of claim 8 , wherein determining the desired phase angle between the phase current and the induced voltage of the AC machine of the generator comprises determining said desired phase angle to achieve an increased efficiency of the generator.

11. The method of claim 8 , wherein determining the desired phase angle between the phase current and the induced voltage of the AC machine of the generator comprises determining said desired phase angle to achieve a faster torque response.

12. The method of claim 8 , wherein determining the desired phase angle between the phase current and the induced voltage of the AC machine of the generator comprises determining said desired phase angle to achieve a faster voltage response.

13. The method of claim 8 wherein determining the desired phase angle between the phase current and the induced voltage of the AC machine of the generator comprises using a look-up table.

14. The method of claim 8 wherein the sensor device configured to determine the rotor position of the AC machine of the generator comprises a Hall-effect sensor with a predetermined resolution.

15. A high efficiency generator system comprising:
an AC machine including a plurality of armature coils producing a multi-phase AC output comprising a plurality of phase voltages;
an active bridge rectifier circuit electrically coupled to the armature coils, said rectifier circuit including a plurality of switches; and
a sensor device for sensing a rotor position of the AC machine;
a control circuit, comprising a processor and memory, to receive the rotor position from the sensor device, determine a desired phase angle between a phase current and an induced voltage of the AC machine based upon the rotor position, determine phase-to-phase voltages from the plurality of phase voltages, compare said phase-to-phase voltages to upper and lower voltage thresholds, control all switches of the active bridge rectifier circuit off at rotor speeds below a predetermined speed, and control the switches of the active bridge rectifier circuit based upon the desired phase angle and the comparison of said phase-to-phase voltages to said upper and lower voltage thresholds at rotor speeds above said predetermined speed to convert said AC output to a DC output and to achieve the desired phase angle.

16. The high efficiency generator system of claim 15 wherein the desired phase angle between the phase current and the induced voltage of the AC machine is further determined based upon achieving an increased output DC current and an increased power of the generator system over a preferred operating speed range.

17. The high efficiency generator system of claim 15 wherein the desired phase angle between the phase current and the induced voltage of the AC machine is further determined based upon achieving an increased efficiency of the generator system.

18. The high efficiency generator system of claim 15 wherein the desired phase angle between the phase current and the induced voltage of the AC machine is further determined based upon achieving a faster torque response.

19. The high efficiency generator system of claim 15 wherein the desired phase angle between the phase current and the induced voltage of the AC machine is further determined based upon achieving a faster voltage response.

20. The high efficiency generator system of claim 15 wherein the sensor device comprises a Hall-effect sensor with a predetermined resolution.

Assignees

• Gm Global Tech Operations Llc

Inventors

• Namuduri Chandra S
• Gopalakrishnan Suresh

Classifications

• B60K1/00

  Arrangement or mounting of electrical propulsion units (B60K7/00 takes precedence; arrangement or mounting of plural diverse prime-movers for mutual or common propulsion B60K6/00) · CPC title

• H02P23/26

  Power factor control [PFC] · CPC title

• H02P9/009 Primary

  Circuit arrangements for detecting rotor position · CPC title

• H02P2101/45

  for motor vehicles, e.g. car alternators · CPC title

• H02P9/00 Primary

  Arrangements for controlling electric generators for the purpose of obtaining a desired output · CPC title